Alternative Surgical Sterilization
Ovariohysterectomy (known traditionally as “spay”)
- Removes the ovaries and uterus, generally at the cervix.
- No heat cycles, no ovarian hormones, no pregnancy possible.
Hysterectomy (“ovary sparing spay”)
- Removes the uterus and cervix, while leaving one or both of the ovaries intact for physiologic, health, and/or behavioral reasons. One ovary will still produce the same hormones and allow the dog to cycle the same as if both ovaries remained, but halves the risk of ovarian cancers which is rare in dogs.
- Ovary is still functional, so heat cycle behavior and small amount of bleeding from vaginal membranes can still occur. Still attracted to males, will stand to mate. Still at risk of sexually transmitted diseases, other infection, or trauma from males. Cannot become pregnant since uterus is missing.
- Surgeon must remove the entire uterus (no “stump”); otherwise, ovarian hormone exposure can cause uterine bacterial overgrowth and pyometra (infection of the remaining uterus tissue). Thus, the surgical incision will be larger than with an ovariohysterectomy.
- Mammary tumors are the only significant health risk remaining after a hysterectomy. Fifty percent of mammary tumors are malignant in dogs. Owners must stay alert to this possibility of mammary tumors as their dog ages.
- Should still be confined away from males for the full three weeks of the heat cycle, to reduce the risk of injury from the attempted act of breeding and sexually transmitted diseases. Heat cycles generally will occur every six to nine months.
- Removal of testicles. No sperm, no pregnancy. Typically won’t mate, but some neutered males still engage in mating behaviors.
- Eliminates risk of testicular cancers and benign prostatic hypertrophy (enlarged prostate).
- Reduces risk of prostatitis (infection of prostate).
- Can reduce inter-male aggression but does not reliably eliminate all.
- Does not always eliminate male marking behavior and should not be expected to stop roaming behavior.
- Removing a piece of the spermatic cord (vas deferens) to prevent transport of sperm from testicles during ejaculation.
- Still fully male otherwise and still will mate and ejaculate fluid.
- Small risk of spontaneous spermatic cord healing, restoring potential fertility.
- Does not reduce risk for prostatitis, which can be life-threatening.
- Good fencing and/or leashing and supervision still necessary when outside to control wanderlust. Wandering and attempts to mate can lead to auto injuries or death.
- Sexually transmitted diseases can also occur.
Why consider an Ovary Sparing Spay or Vasectomy?
No perfect study examining the removal of the sex organs’ effects on all breeds, all medical conditions, and all unwanted behaviors can be performed. Thus, no single sterilization recommendation can fit every dog and owner. The decision to traditionally sterilize, alternatively sterilize, age to perform such procedures, or leave intact rests on a foundation of science, dogma, and culture.
- When breeders require sterilization in their puppy contract, yet dog owners still want the benefit of sex hormones.
- When performance and show dogs will not be used for breeding.
- For dog breeds that are prone to diseases and conditions that may occur more often when sex hormones are removed. Studies have been performed on breeds such as Golden Retrievers, Labrador Retrievers, Rottweilers, German Shepherd Dogs, and Vizslas examining various disease and behavior developments. Results indicate that the health and behavioral benefits of keeping sex hormones may outweigh the health risks of removing them. There is enough genetic breed variation that the studies’ results should not by applied to all other breeds. One should not assume that the presence of sex hormones will outweigh the benefits of traditional ovariohysterectomy or neuter for all breeds.
Before Your Dog’s Surgery
We recommend completing or collecting required paperwork to bring with you so we may process your dog’s admission quickly the morning of surgery. These include:
- Copy of any recent vaccination records
- Copy of most recent rabies vaccine
Want to Learn More?
- Linda Brent, PhD, MBA and Michelle Kutzler, DVM, PhD, DACT. Innovative Veterinary Care. October 26, 2018.
- . Karen L. Overall, MA, VMD, PhD, DACVB, CAAB. DVM360 Magazine. Dec 1, 2013.
- . Karen L. Overall, MA, VMD, PhD, DACVB, CAAB. DVM360 Magazine. Jan 1, 2014.
- American Veterinary Medical Association.
- . Margaret Root-Kustritz, DVM, PhD, University of Minnesota . April 24,2008. akcchf.org.
- . Natalie Isaza, DVM. See page 6 onwards.
- . Sara Fox Chapman, MS, DVM, MRCVS, VetMFHom. The Alpenhorn. June 2014.
- KhawlaZwida and Michelle Anne Kutzler. Journal of Etiology and Animal Health. March 8, 2016.
- Sophia Yin, DVM. March 5, 2009.
- Will Falconer DVM. Dogs Naturally.
- . Emily Hilgenberg. May 23, 2013.
- . (Facebook Group)